Core java Archive

java.lang.NumberFormatException

In this post, we will see about Java.lang.NumberFormatException. java.lang.NumberFormatException occurs where you try to convert any non-numeric String to Number such as Integer, Double, Float or Long. This exception generally occurs when you get input …

Validate phone number in java

In this post, we will see how to validate phone number in java. Validate any international phone number as per E.123 E.123 is a standards-based recommendation by the International Telecommunications Union sector ITU-T. E.123 provides …

System.out.println in java

In this post, we will see about System.out.println in java and how it works. Did you use system.out.println before? I think this is first statement every java developer compiles. It is generally called by the …

Java float vs double

In this post, we will see the difference between float and double data types in java. As you might know, float and double both can be used to represent floating point number in java. We …